Catalytic activities of the alkali metal scats are discussed based on experimental observations in a fixed bed Iluw reactortt atmospheric condition and instrumenttl analysis. LiC(30 wtr) and NaCI(30 wtrk) pro-nuted MgU catalyst showed superior activity to mono alkali metal salts promoted VIgO catalysts based on the Cviell. This suggests that the bialkali metal salts neutralize the nonselective acid sites due to synergistic effect. llureover, it is estimated that the active sites investigate the equilibrium properties of simple fluids distributed between the external hulk phase and the pore phase. Solvation pressures and pore density profile, are cumputod for the system of hard-sphere fluids inide a spherical hard-wall nudel pore. For dilut concentrations. the resulting olvation presures are approximately equal to those in the bulk phase. EEowever, at a moderately dense concentration of n(L4, a weakly oscillatory behavior of the snlwation pressure starts to emerge. hhe apparent maximum and cninirnum peaks are xhibited in the case of nOfi due to the local densiy inhmxtgeneities is O ions.